From 1a8ac29cbffc261f6d7c92e573878110a7dcbd94 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 2 Oct 2015 21:58:32 +0900 Subject: perf probe: Allow probing on kmodules without dwarf Allow probing on kernel modules when 'perf' is built without debuginfo support. Currently perf-probe --module requires linking with libdw, but this doesn't make sense. E.g. ---- # make NO_DWARF=1 # ./perf probe -m pcspkr pcspkr_event%return Error: unknown switch `m' ---- With this patch ---- # ./perf probe -m pcspkr pcspkr_event%return Added new event: probe:pcspkr_event (on pcspkr_event%return in pcspkr) You can now use it in all perf tools, such as: perf record -e probe:pcspkr_event -aR sleep 1 ---- Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/20151002125832.18617.78721.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'tools/perf/util') diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 3010abc071ff..b51a8bfb40f9 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -2543,7 +2543,8 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, goto out; } - if (!pev->uprobes && !pp->retprobe) { + /* Note that the symbols in the kmodule are not relocated */ + if (!pev->uprobes && !pp->retprobe && !pev->target) { reloc_sym = kernel_get_ref_reloc_sym(); if (!reloc_sym) { pr_warning("Relocated base symbol is not found!\n"); @@ -2580,8 +2581,9 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, } /* Add one probe point */ tp->address = map->unmap_ip(map, sym->start) + pp->offset; - /* If we found a wrong one, mark it by NULL symbol */ - if (!pev->uprobes && + + /* Check the kprobe (not in module) is within .text */ + if (!pev->uprobes && !pev->target && kprobe_warn_out_range(sym->name, tp->address)) { tp->symbol = NULL; /* Skip it */ skipped++; -- cgit v1.2.3